Ever wonder why that brilliant idea always comes right before you fall asleep or when you're standing half awake in the shower? According to a recent study in the journal Thinking & Reasoning it's because you're more creative when you're feeling groggy.

In the study, researchers had students complete problem-solving tasks at various points in the day. The student's biggest insights came during their least optimal time of functioning. As a recommendation, the researchers suggest students design their schedules so their creative classes are during these non-optimal points in the day. For many, this is first thing in the morning or during that post-lunch brain slump. For non-students, the same advice makes sense and you can plan your brainstorming time when you're the most tired.